Tag: evs

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Questions Related to evs

Multiple choice evs look, learn and experience matter: states, classification and properties study of matter general introduction: importance and scope of chemistry

Which of the following is not a compound?

  1. Sulphur dioxide

  2. Chalk

  3. Lead

  4. Sulphuric acid
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Lead $(Pb)$ is not a compound. It is an element present in its pure form so it a single homogeneous identity. Compounds have two or more elements present in the uniform composition in the compound state.


Sulphur dioxide $(SO _2)$ is formed by two elements namely, sulphur and oxygen.

Sulphuric acid $(H _2SO _4)$ is a compound formed by hydrogen, sulphur and oxygen.
The chemical formula for chalk is CaCO3 which is made up of carbon, calcium and oxygen.

Hence, option $C$  is correct.

Multiple choice evs look, learn and experience matter: states, classification and properties study of matter general introduction: importance and scope of chemistry

What is the name given to a pure substance with only one kind of atoms?

  1. Element

  2. Compound

  3. Mixture

  4. Suspension
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Element is a chemical substance which is composed of same type of atoms or only of single kind e.g., periodic table consist of all elements in its pure form like $Na,\ Mg,\ Cu,\ Pb$ etc.

Multiple choice evs look, learn and experience matter: states, classification and properties study of matter general introduction: importance and scope of chemistry

Classify which of the following pair is a compound and a mixture?

  1. Air, ocean water

  2. Water, glucose

  3. Glucose, Salt

  4. Water, air
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

In the above examples, water is a compound and air is mixture. Water consists of oxygen and hydrogen chemically combined whereas air is a mixture which consists of oxygen, nitrogen and other gases which are only physically combined.

Multiple choice evs look, learn and experience matter: states, classification and properties study of matter general introduction: importance and scope of chemistry

Define element.

  1. Can be broken down by chemical reactions into simpler substances

  2. Cannot be broken down by chemical reactions into simpler substances

  3. Maybe be broken down by chemical reactions into simpler substances

  4. Both b and c
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A pure substance which is made up of only one kind of atom and cannot be broken into two or more simpler substances by physical or chemical means is referred to as an element. An element is homogeneous in nature; it is a pure substance, made up of only one kind of atoms. For example, iron and silver are made of only iron and silver atoms.

Multiple choice evs look, learn and experience matter: states, classification and properties study of matter general introduction: importance and scope of chemistry

Identify the compounds among the following:


(a) Milk (b) Sodium (c) Calcium Carbonate (d) Methane

  1. Milk, Calcium carbonate

  2. Sodium

  3. Calcium carbonate, Methane

  4. None of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Compounds is a pure substance made up of two or more elements combined chemically in a definite (or constant) proportion by mass.


Calcium carbonate is $CaCO _3$, Methane is $CH _4$ --- Compound.

Sodium ----- Element.

Milk ---------- Mixture.